Merge pull request #192 from lorentey/set-API-checker

[test] Check baseline API expectations for set-like types

Sources/BitCollections/BitSet/BitSet+Extras.swift

@@ -143,6 +143,24 @@ extension BitSet {
 }
 
 extension BitSet {
+  /// Removes and returns the element at the specified position.
+  ///
+  /// - Parameter i: The position of the element to remove. `index` must be
+  ///   a valid index of the collection that is not equal to the collection's
+  ///   end index.
+  ///
+  /// - Returns: The removed element.
+  ///
+  /// - Complexity: O(`1`) if the set is a unique value (with no live copies),
+  ///    and the removed value is less than the largest value currently in the
+  ///    set (named *max*). Otherwise the complexity is at worst O(*max*).
+  @discardableResult
+  public mutating func remove(at index: Index) -> Element {
+    let removed = _remove(index._value)
+    precondition(removed, "Invalid index")
+    return Int(bitPattern: index._value)
+  }
+
   /// Returns the current set (already sorted).
   ///
   /// - Complexity: O(1)

Sources/BitCollections/BitSet/BitSet+SetAlgebra basics.swift

@@ -97,7 +97,7 @@ extension BitSet {
   ///
   /// - Complexity: O(`1`) if the set is a unique value (with no live copies),
   ///    and the removed value is less than the largest value currently in the
-  ///    set (named *max*). Otherwise the complexity is O(*max*).
+  ///    set (named *max*). Otherwise the complexity is at worst O(*max*).
   @discardableResult
   public mutating func remove(_ member: Int) -> Int? {
     guard let m = UInt(exactly: member) else { return nil }

Sources/_CollectionsTestSupport/AssertionContexts/Combinatorics.swift

@@ -9,6 +9,30 @@
 //
 //===----------------------------------------------------------------------===//
 
+/// Run the supplied closure with all values in `items` in a loop,
+/// recording the current value in the current test trace stack.
+public func withEvery<Element>(
+  _ label: String,
+  by generator: () -> Element?,
+  file: StaticString = #file,
+  line: UInt = #line,
+  run body: (Element) throws -> Void
+) rethrows {
+  let context = TestContext.current
+  while let item = generator() {
+    let entry = context.push("\(label): \(item)", file: file, line: line)
+    var done = false
+    defer {
+      context.pop(entry)
+      if !done {
+        print(context.currentTrace(title: "Throwing trace"))
+      }
+    }
+    try body(item)
+    done = true
+  }
+}
+
 /// Run the supplied closure with all values in `items` in a loop,
 /// recording the current value in the current test trace stack.
 public func withEvery<S: Sequence>(

Sources/_CollectionsTestSupport/Utilities/DictionaryAPIChecker.swift

@@ -9,6 +9,11 @@
 //
 //===----------------------------------------------------------------------===//
 
+/// A test protocol for validating that dictionary-like types implement users'
+/// baseline expectations.
+///
+/// To ensure maximum utility, this protocol doesn't refine `Collection`,
+/// although it does share some of the same requirements.
 public protocol DictionaryAPIChecker<Key, Value> {
   associatedtype Key
   associatedtype Value
@@ -42,15 +47,6 @@ public protocol DictionaryAPIChecker<Key, Value> {
 
   init()
 
-  init<S: Sequence>(
-    uniqueKeysWithValues keysAndValues: S
-  ) where S.Element == (Key, Value)
-
-  init<Keys: Sequence, Values: Sequence>(
-    uniqueKeys keys: Keys,
-    values: Values
-  ) where Keys.Element == Key, Values.Element == Value
-
   init<S: Sequence>(
     _ keysAndValues: S,
     uniquingKeysWith combine: (Value, Value) throws -> Value
@@ -90,19 +86,28 @@ public protocol DictionaryAPIChecker<Key, Value> {
     by keyForValue: (S.Element) throws -> Key
   ) rethrows where Value == [S.Element]
 #endif
+}
 
+extension Dictionary: DictionaryAPIChecker {}
+
+/// Additional entry points provided by this package that aren't provided
+/// by `Dictionary` (yet?).
+public protocol DictionaryAPIExtras: DictionaryAPIChecker {
   // Extras (not in the Standard Library)
 
-  mutating func updateValue<R>(
-    forKey key: Key,
-    default defaultValue: @autoclosure () -> Value,
-    with body: (inout Value) throws -> R
-  ) rethrows -> R
+  init<S: Sequence>(
+    uniqueKeysWithValues keysAndValues: S
+  ) where S.Element == (Key, Value)
 
   init<S: Sequence>(
     uniqueKeysWithValues keysAndValues: S
   ) where S.Element == Element
 
+  init<Keys: Sequence, Values: Sequence>(
+    uniqueKeys keys: Keys,
+    values: Values
+  ) where Keys.Element == Key, Values.Element == Value
+
   init<S: Sequence>(
     _ keysAndValues: S,
     uniquingKeysWith combine: (Value, Value) throws -> Value
@@ -118,7 +123,13 @@ public protocol DictionaryAPIChecker<Key, Value> {
     uniquingKeysWith combine: (Value, Value) throws -> Value
   ) rethrows -> Self where S.Element == Element
 
-  #if false
+  mutating func updateValue<R>(
+    forKey key: Key,
+    default defaultValue: @autoclosure () -> Value,
+    with body: (inout Value) throws -> R
+  ) rethrows -> R
+
+#if false
   // Potential additions implemented by PersistentDictionary:
 
   func contains(_ key: Key) -> Bool
@@ -128,5 +139,5 @@ public protocol DictionaryAPIChecker<Key, Value> {
     with body: (inout Value?) throws -> R
   ) rethrows -> R
 
-  #endif
+#endif
 }

Sources/_CollectionsTestSupport/Utilities/SetAPIChecker.swift

@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Collections open source project
+//
+// Copyright (c) 2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
+/// A test protocol for validating that set-like types implement users'
+/// baseline expectations.
+///
+/// To ensure maximum utility, this protocol refines neither `Collection` nor
+/// `SetAlgebra` although it does share some of the same requirements.
+public protocol SetAPIChecker {
+  associatedtype Element
+  associatedtype Index
+
+  var isEmpty: Bool { get }
+  var count: Int { get }
+
+  init()
+
+  mutating func remove(at index: Index) -> Element
+
+  func filter(_ isIncluded: (Element) throws -> Bool) rethrows -> Self
+
+  func isSubset<S: Sequence>(of other: S) -> Bool
+  where S.Element == Element
+
+  func isSuperset<S: Sequence>(of other: S) -> Bool
+  where S.Element == Element
+
+  func isStrictSubset<S: Sequence>(of other: S) -> Bool
+  where S.Element == Element
+
+  func isStrictSuperset<S: Sequence>(of other: S) -> Bool
+  where S.Element == Element
+
+  func isDisjoint<S: Sequence>(with other: S) -> Bool
+  where S.Element == Element
+
+
+  func intersection<S: Sequence>(_ other: S) -> Self
+  where S.Element == Element
+
+  func union<S: Sequence>(_ other: __owned S) -> Self
+  where S.Element == Element
+
+  __consuming func subtracting<S: Sequence>(_ other: S) -> Self
+  where S.Element == Element
+
+  func symmetricDifference<S: Sequence>(_ other: __owned S) -> Self
+  where S.Element == Element
+
+  mutating func formIntersection<S: Sequence>(_ other: S)
+  where S.Element == Element
+
+  mutating func formUnion<S: Sequence>(_ other: __owned S)
+  where S.Element == Element
+
+  mutating func subtract<S: Sequence>(_ other: S)
+  where S.Element == Element
+
+  mutating func formSymmetricDifference<S: Sequence>(_ other: __owned S)
+  where S.Element == Element
+}
+
+extension Set: SetAPIChecker {}

Tests/BitCollectionsTests/BitSetTests.swift

@@ -13,6 +13,8 @@ import XCTest
 import _CollectionsTestSupport
 import BitCollections
 
+extension BitSet: SetAPIChecker {}
+
 final class BitSetTest: CollectionTestCase {
   func test_empty_initializer() {
     let set = BitSet()
@@ -288,6 +290,32 @@ final class BitSetTest: CollectionTestCase {
     }
   }
 
+  func test_remove_at() {
+    let count = 100
+    withEvery("seed", in: 0 ..< 10) { seed in
+      var rng = RepeatableRandomNumberGenerator(seed: seed)
+      var actual = BitSet(0 ..< count)
+      var expected = Set<Int>(0 ..< count)
+      var c = count
+
+      func nextOffset() -> Int? {
+        guard let next = (0 ..< c).randomElement(using: &rng)
+        else { return nil }
+        c -= 1
+        return next
+      }
+
+      withEvery("offset", by: nextOffset) { offset in
+        let i = actual.index(actual.startIndex, offsetBy: offset)
+        let old = actual.remove(at: i)
+
+        let old2 = expected.remove(old)
+        expectEqual(old, old2)
+      }
+      expectEqual(Array(actual), expected.sorted())
+    }
+  }
+
   func test_member_subscript_getter() {
     withInterestingSets("input", maximum: 1000) { input in
       let bitset = BitSet(input)

Tests/OrderedCollectionsTests/OrderedDictionary/OrderedDictionary Tests.swift

@@ -14,7 +14,7 @@ import XCTest
 
 import _CollectionsTestSupport
 
-extension OrderedDictionary: DictionaryAPIChecker {}
+extension OrderedDictionary: DictionaryAPIExtras {}
 
 class OrderedDictionaryTests: CollectionTestCase {
   func test_empty() {

Tests/OrderedCollectionsTests/OrderedSet/OrderedSetTests.swift

@@ -13,6 +13,8 @@ import XCTest
 @_spi(Testing) import OrderedCollections
 import _CollectionsTestSupport
 
+extension OrderedSet: SetAPIChecker {}
+
 class OrderedSetTests: CollectionTestCase {
   func test_init_uncheckedUniqueElements_concrete() {
     withEvery("count", in: 0 ..< 20) { count in

Tests/PersistentCollectionsTests/PersistentDictionary Tests.swift

@@ -12,7 +12,7 @@
 import _CollectionsTestSupport
 @testable import PersistentCollections
 
-extension PersistentDictionary: DictionaryAPIChecker {}
+extension PersistentDictionary: DictionaryAPIExtras {}
 
 class PersistentDictionaryTests: CollectionTestCase {
   func test_empty() {